fruit Food Allergy

Some Topics

  • Bad and Bizarre Allergy Tests

    One frustrating aspect of working with food-related diseases is that confused and confusing people greet you at every turn. Food allergy, sensitivity and intolerance have are topics that have been obscured by nonsense and confusion for several decades. MDs, by in large, remain ignorant of delayed patterns of food allergy and are often not helpful to patients who seek their advice. A series of dubious testing procedures for “food sensitivity” have flourished in the non-medical sub-culture. A number of bad and bizarre "tests and treatments” have caught on as quick and easy methods of dealing with complex problems and have contributed to the aversion some physicians display toward the subject of food allergy. In any other context, some of these tests would be bad jokes or ludicrous charades. What makes the popularity of these fake tests a serious matter is that patients are suffering and are eager for solutions to their chronic health problems. Because they are not getting help from qualified physicians, they are vulnerable to anyone who seems at all plausible and offers tests and treatments for food problems. Here are some examples of doubtful and bizarre tests:

    Provocation Tests by Injection

    Provocation tests by needle injection of food proteins into the skin have been used to determine food sensitivity. While these test are the most plausible of the group of the bad and bizarre tests, they do not do what they promise and should not be used to determine what the patients can eat. The intradermal (ID) injection test will occasionally show a delayed, cell-mediated response in 24-48 hours. Symptoms may develop as injected antigen reacts with skin mast cells, or reaches circulating basophils and triggers an amplified, immediate alarm-response. There is no question that injected antigen can sometimes demonstrate symptom-production in the allergic patient. Indeed, every allergist is concerned about triggering life-threatening anaphylactic reactions with any injection. If major symptoms do occur with one injected antigen, further testing is invalid for several days.

    Clinical ecologists have claimed to "neutralize" the reaction by injecting further doses of antigen at different concentrations, and often test many substances in one session, lasting several hours. We do not believe any meaningful conclusions can be drawn from these testing marathons.

    The subject tends to have fluctuating, confusing sensations, and is extremely vulnerable to suggestion from the testing person. The ID provocation test is not reliable in predicting responses to foods actually eaten, and should not be used as the basis for recommending diet revision. A small study by Jewett and associates in California questioned the validity of provocation tests; 18 patients were tested by this method and they concluded that subjects had difficulty differentiating active from inactive solutions and that the neutralizing effect was not related to the concentration of the active ingredients.

    This study failed to support the method of provocative-neutralization "allergy" testing - fair enough, but an associated editorial in this esteemed journal used this result to further a widespread prejudice against food-sensitive patients; with the byline, "Food Sensitivity or Self-Deception", the editorial hints darkly that all patients with food allergy are dupes. We have noticed over the past 15 years, that the mention of food allergy invites prejudiced if not hostile opinions from many members of the medical establishment. Indeed, some of the worst examples of dogmatic and irrational thinking can be elicited from MDs by food allergic patients. The only conclusion we can reach about provocation tests and this study is that if subjects are asked to sit in a room for several hours after breakfast or lunch, receiving a variety of injections, with a variety of distractions and suggestions, explicit or implicit, from testers and other subjects, everyone will come to the wrong conclusions about what is really going on. The authors of this study did not seem to realize that any group of subjects sitting in a room will report symptoms, if asked. This is not a mysterious "placebo" effect; but the "noise" of each person's body, which becomes apparent to everyone who sits quietly and does nothing for a few hours. They may be reacting to foods they ate before they arrived for the tests.

    Cytotoxic Tests

    Cytotoxic tests were offered in the early 80s for definitive "food sensitivity" determination and were condemned by the American College of Allergists as ineffective. Cytotoxic tests expose blood cells to food extracts in a chamber viewed through a microscope; cell counts before and after reveal cell damage. Automation can be applied to cell counting and evaluation with computer print-outs of test results. While the earlier cytotoxic tests have little to offer, more sophisticated analysis of food antigen and blood-cell interactions is always relevant to understanding pathogenic mechanisms. An automated test has been offered as the ALCAT diagnostic system. The ALCAT brochure repeats the understanding that multiple mechanisms are involved in food allergy and that responses to food antigens by various blood components should be measured in food allergic individuals. The predictive significance of these measurements remains to be discovered.

    Muscle testing

    Muscle testing is one of the bizarre charades used to demonstrate "food and chemical sensitivity". The subject is invited to hold a glass vial containing the test substance and the examiner tests the strength of the other arm that is outstretched. Sometimes the subject is instructed to hold the vial over the body part to be tested. Weakness is interpreted as a food reaction, and the subject is advised to avoid the test substance. Variations on this theme have emerged. As a party game, muscle testing could be fun. Anyone who believes that this is a valid test of body physiology needs to be re-educated in biology. Muscle testing is a worthless scam if you are paying real money to be "tested."

    Vega Meter

    A simple resistance meter, dressed up in a fancy box (Vega meter), is used to measure skin resistance between a ground plate and an "acupuncture point", usually at the thumb web. A glass vial, containing test substances, is placed somewhere (it doesn't seem to matter where) in the circuit. Meter readings are interpreted as "positive or negative reactions". The more imaginative Vega meter readers will tell you that they can balance levels of certain substances in your body by doing meter readings and prescribing drops.

    You might sign up for a series of tests and treatments and the cost can vary from hundreds to thousands of dollars. Too good to be true? Of course, Vega meters are scams. A pseudo-science explanatory system, referring to "oscillations in the electromagnetic field", confuses and misleads the sincere patient who just wants to get better.

    Feathers, Crystals, Fantasy

    We have seen machines, tests and treatments that go from impressive scams and charades to the ludicrous and ridiculous. One patient, for example, brought 4 pages of food test results from a homeopathic practitioner who used a crystal and a feather to evaluate her food sensitivities. This was a neatly hand-written list showing the many foods tested and her sensitivity to them, presented as a percentage: she was 80% sensitive to milk and so-on. Many balancing potions were prescribed and she was to avoid the foods that had high percentage scores on the "tests". She did improve on this regimen because she stopped eating many problem foods; however, she soon lost her way and became confused about what she should do long-term. We would all like either a futuristic machine that could give us all the answers or the super-human ability to simply write down the reactive repertoire of each person, but the emperor has no clothes! Vega machines, muscle tests, feathers, pendulums and crystals belong in the magician’s bag of tricks or the hypnotist’s stage show but are not part of a sincere practice of medicine, using valid and reproducible techniques. If you have paid real money for these tests and associated treatments, you have been cheated.

    Live Blood Cell Analysis

    The idea is that you put a drop of blood on a microscope slide and look at the living cells. This could be a good idea, but there are serious flaws when this procedure is offered as diagnostic test for food allergy or food toxicity. So far, we have not been convinced that any office-based live cell analysis is valid. The analysts, in our opinion would have difficulty identifying which cell types they were observing. They have no way of differentiating cell-damage artifacts from real pathology. Their displays of cell abnormalities appear to be mostly artifacts, and their diagnoses defy biological knowledge. We would bet big money against the reproducibility of this technique. Any takers?

    Experienced microscopists know that looking at living specimens under the microscope changes the specimen. Viewing live cells is difficult because they have to be suspended in a nutrient solution, at the right temperature. It is challenging to keep them alive. Heat from the light source tends to dry cells; the water in which they are suspended evaporates and the cells pucker up, change shape and develop abnormal looking membranes. They may stick together. There are artifacts, in other words, that an uncritical observer can interpret as evidence of disease. Even if the lab has expensive equipment and expertise to keep the cells alive and in good condition, the observer has to be familiar with different cell types, understand their morphological characteristics and behavior. There are possibilities for advanced systems of live blood cell analysis. We would like to know more about how blood cells behave in vivo, and it is possible to simulate living conditions under the microscope, although expensive equipment and skilled operators are prerequisites. There are proper techniques for observing how specific living blood cells behave when exposed to specific stimuli. One test, for example, observes whether lymphocytes begin to multiply when they are exposed to an antigen. A clinical test based on this idea could be useful. This is a research project, not a validated diagnostic method and certainly not a technique that can be done by amateurs.

    Listen to the Bad and Bizarre Tests for Food Allergy